The present invention relates to trailer hitches, and more particularly, to trailer hitches for fifth wheel or gooseneck type trailers supported such as in the bed of a pick-up truck and which are operated by mechanical controls.
Fifth wheel and gooseneck type trailers are used with pick-up trucks to support and tow a trailer by placing the weight and load of the trailer generally over the rear axle of the pick-up truck rather than over or adjacent the rear bumper. Hitches for fifth-wheel and gooseneck trailers have found a large and long-standing acceptance in the marketplace for towing a wide variety of trailers.
One common type of fifth-wheel trailer includes a kingpin which extends generally vertically on the leading tongue of the trailer. The hitch engages the trailer by surrounding the kingpin. One example of such a fifth-wheel hitch is disclosed in U.S. Pat. Nos. 6,846,000 and 6,935,650, which includes two movable plates or jaws which engage around the kingpin. The hitch disclosed in U.S. Pat. Nos. 6,846,000 and 6,935,650 has a control lever for moving the jaws to release the kingpin. A safety pin provides a positive locking feature which prevents unintended release of the hitch.
An example of a gooseneck hitch is disclosed in U.S. Pat. No. 6,533,308, which includes a pop-up ball rather than kingpin engaging jaws. The gooseneck hitch disclosed in U.S. Pat. No. 6,533,308 includes a raising/lowering linkage with a handle which extends into the rear wheel well of the pick-up truck, a convenient spot for the operator to control the operation of the hitch without climbing into the bed of the pick-up truck.
The average operator of a fifth-wheel or gooseneck hitch is not young, such as over 55 years old, who is perhaps not as strong and nimble as he or she once was. The controls of the hitch should be readily accessible by the operator, without requiring too much climbing or bending to access. Operation of the controls should not require the application of excessive force or torque. The hitch must be strong to securely engage the trailer, minimizing the possibility of breakage or of any way the trailer could inadvertently come loose. At the same time, the hitch should be simple to operate, so the operator has no difficulty in intentionally engaging and disengaging the trailer. The hitch should preferably be mechanically operated, so there is no possibility of a loss of power preventing operation of the hitch. The hitch must be robust and reliable, to last for carefree operation over the life of at least one vehicle, and possibly over the life of several vehicles, despite the fact that the hitch will likely be openly exposed to weather over its years or decades of use. As much as possible, the hitch should also have minimal cost and expense in manufacturing and assembly.